This occasionally happens when updates are applied via the terminal by an apt upgrade. As an alternative to this bub, please consider reopening 347602. Note that I am on kubuntu 17.10 with the kubuntu ppa, so my system is receiving updates tracking the kde plasma/framework releases. According to this, I am getting a feeling that this bug is a regression that has started with one of the latest KDE upgrades.
*** This bug has been marked as a duplicate of bug 392063 ***
*** This bug has been marked as a duplicate of bug 385754 ***
*** This bug has been marked as a duplicate of bug 394043 ***